This invention relates to cassettes of the type including a length of tape having end portions wound around two reels rotatably mounted in a housing with a portion of the tape extending between the reels, and a tab for limiting slack in the tape between the reels.
Slack or looseness in the length of tape between the reels in such a cassette can arise when the cassette is being transported or is otherwise separated from a recording or reproducing device. While some cassettes have locks that restrict rotation of the reels when the cassette is not in a machine, it is still possible that one or both of the reels within the cassette may turn in the direction of unwinding to develop slack. Slack in the tape can also occur when the tape is engaged with a recording or reproducing device. Typically, the recording or reproducing device has spindles which engage the two reels. If driving and braking of the reels during the operation of the recording or reproducing apparatus is not synchronous, slack in the tape will develop. This slack may cause the tape to jam within the cassette or within the recording or reproducing device engaging the tape.
Cassettes having tabs to limit the slack in the tape are known in the art. For example, a flexible resilient slack limiter tab is described in U.S. Pat. No. 3,797,799. One end of the slack limiter tab biases tape in a cassette into engagement with a fixed support surface to cause a slight resistance to motion of the tape. The slack limiter tab is secured in position by cementing or adhesively fastening a portion of the tab to the housing of the cassette.
Adhesively fastening a slack limiting tab in a cassette requires more time than is desirable, particularly for highly automated assembly. Also adhesively fastened slack limiter tabs may become misaligned during installation, or the adhesive may fail after installation. Misalignment of the tab may cause excessive wear on the tape or improper performance of the tape. Adhesive failure, which can occur due to age, humidity, or stress on the tab due to misalignment during installation, may result in the tab being dislodged from its desired position, and even jamming of the dislodged tab in the cassette or in a machine in which the cassette is mounted.